Centrifugal spraying device



10, 1961 E. o. NORRls 2,967,668

CENTRIFUGAL SPRAYING DEVICE Filed Feb. 5, 1959 4 Sheets-Sheet 1 ATTORNEY Jan. 10, 1961 E. o. NoRRls CENTRIFUGAL SPRAYING DEVICE Filed F'b. 5, 1959 mvram'oR E0 WA eo O. /VORR/s 4 Sheets-Sheet 2 aa.. l

ATTQRNEY Jan. 10, 1961 E. o. NoRRls CENTRIFUGAL SPRAYING DEVICE Filed Feb. 5, 1959 4 Sheets-Sheet 3 ATTORNEY Jan. 10, 1961 E. o. NoRRls 2,967,668

-CENTRIFUGAL SPRAYING DEVICE I Filed Feb. 5, 1959 4 Sheets-Sheet 4 /47 l NTOR 50W/ifa O. OEE/5 ATTORNEY CENTRIEUGAL SPRAYING DEVICE Edvr'ard 0.Norris, Ledgevmoor Lane, Westport, Conn. Filed Feb. s, 1959, ser. N0. 191,303

` s (ci. 2319-15) The present invention relates to centrifugal spraying devices.

One `known type of centrifugal spraying device for use, for example, in applying paint or other surface finishing material, comprises a .rotary intercepting and collecting bowl., la lrotary atomizer 'having its axis tilted in relation to the axis ofthe bowl, so that an angular or sectoral part of the spray 4material discharged from the periphery ofthe atomizer is intercepted by the bowl and collected therein, while the remaining part of the spray material discharged from the lperiphery of the atomizer is -freefor directional kdischarge towards the object to be sprayed, means `for continuously feeding spray material tothe atomizer, and means for conducting the intercepted s pray material for redirection towards the atomizer.

One object of the present invention is to provide a United Statesv Patent new and :improved centrifugal spray device -of the -geni eral type described.

Another vobject of the invention is to provide a centrifugalspray ,device of the general type described `having new ,and limproved means for conducting the intercepted and collected spray material from the collecting bowl for redirection towards the atomizer.

Another object of the yinvention is to provide a centrifugal spray device of the general type described having the means forfeeding ,the spray material to the atomizer and the means for conducting the intercepted and collected Vspray material from the collecting bowl, for redirect-ion towards the atomizer, -so constructed, as to correlate `their :functions in :a :new and `improved manner. Atfurther 'object (of theinvention is to provide a centrifugal spray Ydevice of the `general type described having -th'e means for feeding the sprayl material to the atomizer and the means for conducting the vrintercepted and collected spray material `from thev collecting bowl for vredirection towards the atomizer, so correlated Vas to regulate automatically the pressures between said means.

v=Anotherobject of the invention is to provide a centrifugal spray device of A,the general type described, which has a `jet for 'feeding spray .material to the rotary atomizer and a scoop for picking up;the interceptedand collected spray material lefromithe rotary collecting bowl and kfor redirecting 'it to ,the jetyand which is designed to permit the scoop and vthe jet ,to Abe easily removed for ready change, y repair or cleaning.

Another object of the invention is to :providela centrifugalispray device fof lthe *general'type described having a scoop :for picking up the intercepted and Ycollected -spray materialfrom an annular channel-in the collecting bowl and lreturning `it for delivery to the atornizing 4system .of the spray device, and :having a nose at the end `of `.the scoop designed to-pick up the material from the channel effectively and yto prevent the solids fromV separating out of the material inthe channel by centrifugal force, `so as yprevent excessive .wear :of 4.the nose andy plugging of thescoop as a result ,Aof such fseparatediso'lids.

A further-.object of Ythe :invention is'fto provide a veentrifugal spraying device which is operated under the influence ofan Ielectrostatic charge or field emanating tion of air in the region of said periphery, so that contlicting space charges around the atomizer are minimized.

Another object of the invention is to provide a centrifugal spray device of the general type described having a scoop for the purpose described, and means for dellecting the material which collects on the exterior of the scoop towards a rotary part of the device where it is subjected to centrifugal movement, thereby preventing this material from accumulating in regions where it might interfere with eficient operation.

Still another object is to provide a centrifugal spray device of the general type described, which is designed to provide maximum effective material discharge areas on `the rotary atomizer with an atomizer of minimum effective diameter.

` A further object of the invention is to provide in conjunction with a centrifugal spray device a control system which permits immediate shut-off and immediate start of Vspraying operations when such operations are initiated by the actuation of the appropriate control, and which prevents such accumulation of-spray material in the device upon shut-down, as would hamper immediate restarting operations.

Various other objects of the invention are apparent from' the following description .and from the accompanying drawings, in which 1 Fig. 1 is a vertical section of a centrifugal spray device constituting one embodimenttof the presentinvention;

' Fig. 2 is a detailsection of thecentrifugal spray device taken on lines Z- Z of Fig. 1;

Fig. 3 is `a vdetail vertical section of the centrifugal spray device taken approximately along the lines 3-3 vof Fig. 2 and then turned 180;

Fig. 4 is a vertical section of the head of a centrifugal spray device constituting another embodiment of the present invention and ktaken along lthe lines 4-.4 l,of Fig. 5; i

`Fig. 5 is asection of thecentrifugal spray device taken approximately along the lines 5-5 of Fig.` 4;

AFig.,6 jis a fragmentary section o f the head .of a centrifugal ,spray device constituting Vanother embodiment of the lpresent invention;

AFig. .7 is a detail section of a centrifugal spray device constituting still another embodiment of Ythe present invennen;

Fig. 8 .is a detail section of -the centrifugal spray def i vice taken on lines 8,- 8 of Fig. 7;

Fig. f9 shows an Vapparatus partlyin side elevationand partly in section for controlling a centrifugal spray device in accordance with certain features of the present invention;

Eig. l0 is an enlargement of part ofthe control apparatus .illustrated in Fig. 9 and shows the main control valve -thereof in lclosed position vduring shut-down of the centrifugal spray device;

Eig. .1.1 vis la ,section ofthe kmain control valve illnsf trated in Fig. ,10 but vshows Ysaid valve in open position during operation of the centrifugal spray ldevice; Y

A Fig. 12 is a Ysection of the control Lapparatus `maken on a centrifugal lspray device 1 0 comprisinga ,distributor l head 11 mounted on a fixed post or stancfhion l1 2 shown intheformbf a tube `nladeof suitable material, such as plastic and-carrying axially thereof -a `shaft 13, whichv Patented Jan. 10, 1961 i" s mounted for rotation in an upper ball bearing 14 and a lower ball bearing 15. The lower end of shaft 13 is connected to the shaft 16 of a motor 17, as for example, by an Oldham coupling 18. The centrifugal spray device including the motor 17 are shown adjustably mounted on a bracket 20, which in turn is adjustably secured to a rod 21 by a nut 22. For adjustably mounting the centrifugal spray device 10 on the bracket 20, the bracket has a round recess 23 to receive snugly a round plate 24 secured to the lower anged end of the stanchion 12 by means of studs 25. A series of clamps 26 secured to the bracket 20 by means of thumb screws 27 bear against the plate 24. With the arrangement shown, the centrifugal spray device 10 can be adjusted about the rod 21 and can be adjusted about axis of the shaft 13.

The distributor head 11 comprises an inverted rotary dished hub 30, which is secured to the upper end of the shaft 13 by a nut 31 threaded on said shaft and bearing against the upper side of said hub and which is adjusted to the desired axial position by means of a spacer washer 32. This hub 30 is provided with a peripheral internal surface 29 flaring radially outwardly so that spray material is caused by centrifugal force to ow outwardly therealong to the rim of the hub.

A rotary atomizer 33 in the form of a disc and more specifically shown in the form of a ring is secured to the lower side of the hub 30 by screws 34. The hub 30 has a depending skirt 35 seated on the atomizer 33 and provided with a series of circumferentially spaced notches defining openings 36 with the atomizer for the ow of material therethrough. The atomizer 33 has an annular flange 37 with an upper radially outwardly extending flow surface 38 communicating with the openings 36 and terminating in a peripheral edge 40 from which the material is ejected as an atomized spray by centrifugal force. The lower side of the atomizer 33 has a V-shaped peripheral rib 41 located below the open end of an encompassing rotary bowl 64 to be described and adapted to propel any material which may have found its way to this lower side centrifugally outwardly for interception by the bowl before said material reaches the ejection edge 40 of the atomizer. If the material found its way along the underside of the atomizer to its single peripheral discharge edge 40, it might interfere with the orderly discharge of the material from said edge coming from the upper ow surface 38 of the atomizer.

A fixed closure 45 for the lower side of the distributor head 11 embraces the xed stanchion 12 and is 'secured to the upper end of said stanchion by studs v46. lThis closure 45 has a cylindrical extension 47 servingv as a bracket and carrying at its upper end the outer race 48 of a bearing S0, the axis of which is disposed at an angle to the axis of the shaft 13. The bearing 50 is provided with an inner race 51 which is carried by a rotary ring 52 disposed internally of the bearing and rigidly secured to a flange at the upper end of a ring 53. This ring 53 extends around the bracket 47 and has a labyrinthic running seal 54 with the fixed closure 45. Integral with and extending around the ring 53 is a larger outer ring 55 provided with an upwardly flared internal ow surface 56 and spaced therefrom by an annular passageway 57. The outer ring 55 extends into the cavity of the hub 30 but is spaced radially inwardly from the internal flaring surface 29 of the hub 30 and is connected to the inner ring 53 by a web 58 having a series of openings 59 to permit flow of the material through the passageway 57. At its lower end, the outer ring 55 carries integrally a dished radial wall 60 to the outer periphery of which is secured, as for example, by integral formation therewith an annular wall 61 tapering upwardly toward its upper open end and connected at its lower end to a bottom closure wall 62 by means of studs 63 to form with said closure wall a rotary spray intercepting and material collecting bowl 64. This closure wall 62 is in the general form of a dished annular ring and has a labyrinthic running seal 66 with the xed closure 45 of the distributor head 11, and the rim of the annular bowl wall 61 has a projecting lip 65 designed to intercept any material that might fall on said rim and to project it radially outwardly instead of permitting it to ow downward along the outside of the bowl.

The radial wall 60 defines with the closure wall 62 a scoop chamber 67 in the bowl 64 and said radial wall 60 has a series of passages 68 at its outer periphery adjacent to the annular bowl wall 61 to pass material which is intercepted by the annular wall downward into said scoop chamber.

The annular bowl wall 61 is tapered towards its opposite ends and at the annular junction between the tapering sections of said wall at the outer periphery of the scoop chamber 67, said bowl wall has a peripheral groove 72.

The shaft 13 drives the atomizer 33 through the hub 30 and also drives the bowl 64. To effect the drive to the bowl 64, the inner surface of the ring 52 secured to the inner race of the bearing 50 bears against a cone 75, which is slidably held on the shaft 13 and which has its conical surface pressed against the inner surface of the ring 52 by a coil spring 76 in friction drive contact therewith. The cone 75 is keyed to the shaft 13 for rotation therewith while it is permitted to slide along said shaft, so that the cone 75 is maintained in friction drive contact with the ring 52.

Fixed conduit means for handling the material to bc sprayed is substantially in the form of a Y or T and comprises an inlet pipe 80 with two branches 81 and 82. The branch 81 extending substantially radially in the scoop chamber 67 serves as a scoop to return the such as paint.

material intercepted and collected in the bowl 64 towards the.atomizer 33 and the other branch 82 in the form of a jet extends upwardly into the lower end of the passageway 57 substantially parallel to the axis of the ring 53 and below the web 58 and serves to conduct the material to the ring surface 56 for ow under centrifugal action towards the atomizer 33. The conduit means is constructed to permit its component parts to be easily assembled or disassembled to facilitate cleaning, repairing or replacement.

YIn the specific form shown, the conduit means comprises the inlet pipe 80 shown in the form of a fitting screwed into the fixed closure 45 and connected by a hose 85 to a source of fresh material to be sprayed, This pipe 80 has a neck 86 with a series of Vtransverse holes 87 therein and a head 88 above said neck, and the jet 82 seats on said head and is pressed against an annular shoulder in the closure 45 by the pressure of the tube 80 screwed into the closure, so that the jet 82 may be removed for inspection and cleaning municating with said passage.

without disassembling the unit. The closure 45 has a passage 90 between the chamber surrounding the apertured neck 86 of the inlet tube 80 and the scoop chamber 67, and screwed into said closure is a fitting 91 com- Fitted into the fitting 91 with a snug sealing slide fit is the scoop 81 shown in the form of a tube, the inner section 92 extending radially of the bowl 64, the outer section 93 being curved in a direction opposite to the direction of rotation of the bowl, as shown in F ig. 2 and terminating in a nose inthe vicinity of the bowl wall 61.

. The scoop 81 receives support in addition to that afforded by the fitting 91, without interfering with its easy removal, and for that purpose, there is provided a bracket plate 95 secured to the closure 45, as for example, by welding or soldering, and fastened by screws 96 to a mounting plate 97 affixed to one side of the scoop 81, as for example, by soldering. For removing the scoop 81 for cleaning, repair or replacement, the bottom wall 62 of the bowl 64 is removed after loosening the studs 63, and the fitting 91 is unscrewed from the closure 45 causing it to slide along the scoop to the dot and dash position shown in Fig. 2 where it is clear of the closure.

Upon removal ofthe screws 9,6, the scoopv .81.,with at tached Vmounting plate '9.7 may be swung thedirection of the arrow A in Fig. .2 and out ofthe 'opening vat the bottom of the bowl 64 presented by thexremoval Aof the bottom wall l62 Vof said bowl. l

At 'its .outer nose end, the scoopV 81 is provided on its forward side with a deilector 100 lsecured to the scoop, as for example, by soldering y'to .direct the intercepted` material vaccumulated in the outer4 periphery of the scoop chamber 67 into the mouth of the scoop and isprovided on its real* side with a Vplow tip 101 of 'cemented or lsintered tungsten carbide or similar -hard material secured to thescoop, as for. example, by soldering y,and extending into the peripheral `groove 772 of the bowl. As the bowl 64 rotates in the direction of the arrow in Fig. 2, the 'plow itip 101 stirs up the material vin the groove 72 causing the material to .be mixed and preventing thereby solids 'from separating out of the material in fthe groove by centrifugal force. .Separated solids tend to vwear out the scoop nose quickly and to., plug up the scoop.

The .centrifugal spray device is preferably constructed to operate not only under centrifugal action but also under the inuence of an electrostatic charge or field. For that purpose, .the fixed stanchion 12, and the rotating parts of the device except the shaft 13, the different bearings and the atomizer 33 may be made of electrical non-conducting material, such as plastic, and a suitable charging electrode may be provided for applying an electrostatic charge to the spray material before it leaves the atomizer. For example, high tension current may be supplied -to the shaft 13 'through its lower bearings 15, and the hub 30 although made of nonconductive material, such as a phenolic composition, has a conductive coating along its internal surface 29 extending between the yconductive shaft and the conductive atomizer 33.

As the atomizer 33 rotates, air inthe region of its discharge peripheral edge 40 becomes ionized and may have a distracting and disruptive influence on the orderly arrangement and travel of the atomized material to be sprayed towards the article to be sprayed. To minimize this eifect, the hub 30 has a contoured air deiiecting peripheral flange 110 presenting an upwardly and radially outwardly curved surface l11 facing the upper .flow surface 38 ofthe atomizer 33 and adapted to lead the air away from said surface as the hub and atomizer rotate. v To prevent material that hasV passed through the openings 36 vfrom climbing along the lsurface 111 of the deilector ange 110, rthe hub v30 is provided with :a peripheral notch 112 below the iiange, and the atomizer 33 is'provided with a short circumferential ramp 113 leading from the lower side of said notch and from the openings36 tothe upper flow surface 38 of the atomizer 33.

-In operation, the material supplied through the inlet pipe 80 is fe'd throughthe jet 82 into the passageway 57, and iiows through the holes 59 and by centrifugal action along the internal aring flow surface 56 outwardly over the rim of the ring 55 and then radially along the flaring surface r29 of the hub Y30 towards the openings 36. The material then flows by centrifugal action through the 'openings 3'6, along 'the ramp 1-13 of the atomizer 33 'and then 4along the upper iiow surface 38 of said atomizer until it reaches the peripheral `edge 40 of said atomizer from which it is discharged'outwar'dly as an atomized spray. The atomizer 33 and the bowl 64 being ymounted to rotate 4about non-parallel axes,

'the bowl'intercepts a sector portion of the spray ejected from the periphery 40 ofthe atomizer 33, while ythe remainder 'of the spray of predetermined angle travels directionally towards the article to be sprayed. The .angle .off intercept of the bowl 64 `with the material discharged y from the atomizer33 depends Vupon the angular relationship between the 'axes Vofl the bowl and of the` atomizer and also lthe axial relation of the atomizerA on the. shaft 13. Hence, the spray Iwidth can be'deterll Any material` intercepted Vby the bowl 64 tiows through the passages 68 in the radial wall 60 and into the scoop chamber 67, is picked up by the scoop 81 thereinand is pressured through said scoop bythe rotation of the,` bowl into the jet 82 where it joins the fresh material fed into the jet from the inlet pipe 80. This permits the intercepted material, which may have become more viscous, to be mixed with the fresh material prior to spraying, so that a uniform sprayvis maintained.

One important advantage of interconnecting the scoop 8,1 andthe jet 82 into a branch system vis that it creates automatically pressure conditions that control 'flow through the scoop in either direction according to the amount of intercepted material in the bowl 64. 'For example, at `the start of spray operations, the scoop cham-V ber 67 is empty and the pressure conditions in the scoop chamber 67 are such, that the fresh material from the inlet vpipe is fed under pressure to the jet 82 fordelivery to the atomizer 33 but also through the scoop 81 in ya radially outer direction to the outer periphery of the scoop chamber 67 to Viill said periphery, until the back pressure in the scoop is equal to or slightly greater than the material feed pressure, whereupon the material ows in the opposite direction in the scoop towards the jet 82 `where it is mixed with fresh material. The back scoop pressure serves to oppose feed pressure in the 'inlet pipe 80 `so that an excessively high feed rate to the atomizer 33 is prevented and flooding of `thedistributor head 11 is obviated.

Another advantage of interconnecting the scoop 81A and the iet S2 into a branch system is ,that itpermits the use of a relatively large diameter jet and assures maxi-v mum jetting action therewith.

In the following description of different modifications of the invention, the parts thereof corresponding Vto the parts in the yconstruction of Figs. 1-3 are designated ,by the same reference numbers but with subscript letters a `and b.

Figs. 4 and 5 show a modified distributor head -11a in which a shaft 13a has connected to its'upper end Aan inverted rotary dished hub 30a by a nut 31a threaded on said shaft and bearing against the upper side of said hub. This hub 30a is adjusted to the desired axial position by means of a spacer Washer 32a. A dishedrotary atomizer 33a in the form of a ring is secured `to the lower side Iof the hub 30abyscrews 34a, and a dished or conical guide or feed ring is secured to the lower sideof the atomizer by the same screws. The hub 30a, the atomizer 33a and the guide ring 120 are in nested relationship and in .face to face contact, the hub vseating on the atomizer and the atomizer seating I'on the `guide ring. Radially beyond the region of `seating contact of the hub 30a and the'atomizer 33a is an annular aring flow passage 121 along the top of the atomi'zver'leading to a radial flange 122 on theatomizerand then to `the upper of two separate axially spaced peripheral spray discharge edges 123 and 1124 on said flange, and radially "beyond the region of seating contact of the atomizer 30a kWith both surfaces of the atomizer 33a active for geen# trifugal flow, a spray substantially twicethe volume of material may be atomized to a suitable particle size;

rIn the construction of Figs. -44 andithe 7 has a ange 58a, which is screwed to the outer ring 55a to form an annular passageway 57a between said rings and which has a series of peripheral notches to form openings 59a which said outer ring. The outer ring 55a integrally carries at its lower end a dished radial wall 60a to the outer periphery of which is secured, as for example, by integral formation therewith an annular wall 61a tapering upwardly towards its upper open end and connected at its lower larger end to a lower closure wall 62a by means of studs 63a to form with said closure wall a rotary spray intercepting and material collecting bowl 64a. This closure wall 62a is shown comprising two different annular units 130 and 131 secured together by studs 132 and has a labyrinthic seal 66a with the fixed closure 45a of the distributor head 11a. This fixed closure 45a is screwed on to the fixed stanchion 12a and not only forms the labyrinthic seal 66a with the closure wall 62a but also forms the labyrinthic running seal 54a with the lower part of the inner ring 53a.

The radial wall 60a defines with the closure wall 62a the scoop chamber 67a in the bowl 64a and said radial wall has a series of passages 68a at its outer periphery adjacent to the annular bowl wall 61a to pass material which is intercepted by the annular wall downward into said scoop chamber. The annular bowl 61a has a groove 72a at the outer periphery of the scoop chamber 67a to receive the plow tip 101a at the nose end of the scoop 81a extending in the scoop chamber.

The fixed branched conduit system to form the jet and scoop for the distributor head 11a comprises the inlet pipe 80a connected by the hose 85a to a source of fresh -material and passing through the fixed closure 45a and then forks to form the scoop 81a extending into the scoop chamber 67a and the jet 82a extending into the passageway 57a and having its terminal discharge section 135 extending circumferentially around the inner periphery of the ring 55a.

The scoop 81a is rigidly secured to a stiffening plate 97a, as for example by soldering. When the fixed scoop 81a is disposed in an upward direction in the operation of the spray device, some of the material tends to run down along the scoop and collect and thicken on the stationary closure 45a of the distributor head 11a. To prevent this adverse condition, a baffle 137 rigidly secured to the scoop 81a near its nose, as for example by soldering, and in the form of an angle having its two webs sloping towards the opposed walls of the scoop chamber 67a, deects the material from the scoop onto the rotating surfaces of the walls 60a and 62a, whence it is returned towards the outer periphery of the scoop chamber, where it is picked up by the nose of the scoop.

Except as otherwise described, the construction of Figs. 4 and 5 is similar to that of Figs. 1-3, and operates in a similar manner, except that the material after leaving the ring 55a by centrifugal action passes through the two sets of openings 126 and 127 and onto the two active surfaces of the atomizer 33a for discharge from the two separate peripheral edges 123 and 124.

The modification of Figs. 6, 7 and 8 contains some of the features of construction of Figs. l-3, and some of the features of construction of Figs. 4 and 5 and in addition contains other features. In the modification of Figs. 6-8, the hub 30b nests into the atomizer 33b to form an annular flaring ow passage 1211; between the hub and the atomizer and is notched to form the openings 36b with the atomizer, leading into said passage. The atomizer 33b has a ange 122b which has its top surface located to receive the material discharged from the annular passage 121b and to serve as the sole iiow surface of the atomizer and which terminates in the single peripheral discharge edge 40h.

The bowl 64b in the construction of Figs. 6, 7 and 8 has the bottom wall 62b and radial wall 60b defining therebetween the scoop chamber 67b and ythe branch conduit system is similar to that of Figs. 4 and 5 in that the jet branch 82b extends into the passageway 57b and has its terminal discharge section b extending circumferentially around the inner periphery of the ring 5Sb.V However, this discharge jet section 135b is provided with a pressure adjustable valve in the form of a spring plate, the discharge jet section being square in crosssection and the spring plate being rigidly secured at one end to one wall of said jet section and normally flexing due to its inherent resiliency towards the opposite wall to close said jet section against discharge. The valve 140 operates according to the pressure in the jet 82b, the amount of opening depending on the pressure in the jet.

The upper rim of the bowl 64b is bevelled and is ser rated to form a series of separate peripheral edges 142 arranged in stepped relationship, so that any material which may collect on the edge will be cast off centrifugally from said edge and will be suitably atomized while any surplus material will drop off to the next edge for discharge therefrom in atomized form, thereby preventing the material from flowing along the outside of the bowl towards the bottom thereof.

Figs. 9-13 show a control system 143 used in conjunction with a centrifugal spray device of the general character described and operable so that at the instant of material feed shut off, substantially all of the material is withdrawn from the outer periphery of the scoop chamber and from the scoop for virtually instantaneous shut off and is rapidly restored to said outer periphery of the scoop chamber and to the jet for an equally instantaneous start of the spray operation, when the appropriate control member is actuated. In Fig. 9 is shown a centrifugal spray device which may be any one of the modifications described, but which for purpose of illustration is shown of thetype illustrated in Figs. 1-3. This spray device 10 comprises the distributor head 1I mounted on the fixed stanchion 12 and is shown in a spray chamber 144 in which the articles to be sprayed may be located. The hose 85 connected to the inlet pipe 80 of the distributor head 11 is connected to a source of material through the control system 143.

The control system 143 (Figs. 9-13) comprises a valve 146 with an inlet 147 connected to the source of fresh material supply and an outlet 148 connected to the hose 85 for delivery to the spray device 10. The valve 146 is shown of the poppet type, and comprises a movable valve member 150 in the form of a poppet extending through a circular port 151 between the inlet 147 and outlet 148 and a valve seat 152 at one end of said port. The poppet 150 has a ange 153 at one end adapted to engage the valve seat 152 in closure position of the poppet shown in Fig. 9, a cylindrical body 154 fitting in the port 151 with a snug slide fit and a tapered end section 15S adapted to define an annular clearance 156 therearound for flow passage in open position of the valve 146 shown in Fig. 1l.

The poppet 150 is operated between open and closed position from Ian air cylinder having a piston therein connected to the poppet. Between the air cylinder 160 and the valve 146 is a bellows 162, one end of which is secured to the end of the casing 163 of the valve 146 by a bushing 164 threaded into said casing, the other end of the bellows being connected by a rod 165 to the piston of the air cylinder 160, so that as the air cylinder piston rod is actuated, the bellows is alternately expanded and contracted. The latter end of the bellows 162 is connected by a connecting rod 166 to the poppet 150, so that simultaneously with the alternate expansion and contraction of the bellows, the poppet 150 is correspondingly moved into valve closing and opening positions. The bushing 164 has an internal bore larger than the connecting rod 166 to form a passageway 167 between the interior of the bellows 162 and the valve outlet 148. V

The air cylinder 160 is of the conventional air motor type well known in the art, and having an air inlet 170 controlled by an electromagnetic device 171 of the solenoid type, which is activated in response to the manipulation of a switch (not sho to admit airV from. said inlet/to one side or other of the piston 'in the air cylinder. When the switch is actuated to start the spraying operation, the air from the inlet '170 is admitted to the right 'side of 'the piston in the air cylinder 160, causing said piston to move towards the 'left (Fig. 9') and this causes the valve 146 to open, permitting thereby `the fresh material to pass from the valve inlet 147 through the valve to' the outlet 148 and then through the hose 85 to the inlet 80 of the spray device 10.

In theoperation of the control system, while the spray device is spraying, the valve 146 is in open position shown in Fig. 1l, and the bellows 162 is collapsed. Whenthe'switch is operated 'for shutoff of the spraying operation, the piston in the air cylinder 160 is 'moved tothe right (Fig. 9), until the poppet 150 moves into closing position againstthe valve seat `152 shown in Figs. 9 and 10. During this valve closing operation, the vbellows 162 is expanding and creating suction, causing the material in the outer periphery of the scoop chamber 67 (Figs. 1 3) and in the scoop 81 to be drawn through the -hose 85, through the valve youtlet 148 .(Figs. 9-1-3), through the passageway 167 and into the expanding bellows. The drawing of the material from the spray device 10 when shut down is initiated -by actuation of the switch, and causes immediate suspension of spraying operation, even though the spray device is still rotating. During this valve closing operation, the body '4 of the valve 4poppet 150 is lin the port 151 lblocking flow therethrough.

When the switch is actuated to restart spraying loperation, the piston lin the air cylinder 160 ismoved towards the left from the position shown in Fig. 9, causing the bellows 162 to contract and forcing the lmaterial in the bellows `and in the passageway 167 through the empty scoop 81 (Figs. l-3) into the outer .periphery of the scoop chamber 67 and into the jet 82. During this bellows contracting operation, the valve poppet150 is moving towards the left (Fig. 9) but the body 154 sliding in Vthe port 151 is still blocking flow through said port, so that the column of material being ,pressured by the bellows 162 is not dissipated through said port.

The filling lof the scoop 81 and the outer periphery of the scoop chamber 67 causes the material when the poppet 150 (Figs. 9-13) reaches thefopen -position shown in Fig. 11 to flow from the valve inlet -147 to the valve outlet l148, and through the inlet 80 of the spray device 10 -directly into the jet 82 (Figs. 1-3) towards `the atomizer 33, and also to the scoop, thereby causing immediate start of spraying operation.

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto but is to be construed broadly and restricted solely by the scope of the appended claims.

What is claimed is:

1. A spraying system comprising a centrifugal spray device including a rotatable atomizer defining an annular flow surface along which the material to be sprayed flows under centrifugal action and having a peripheral discharge edge, a rotary bowl having its axis tilted in relation to the axis of said atomizer for intercepting part of the spray projected from said edge and collecting the intercepted material, means forming in said bowl an annular scoop chamber extending radially outwardly and rotatable with said bowl, said scoop chamber having means to cause the material intercepted in the bowl to ow thereinto, a stationary scoop disposed in said scoop chamber and arranged with its nose end at the outer periphery of said scoop chamber, an inlet feed pipe arranged to deliver fresh material to the device, said scoop near its other end having a connection with said feed pipe, and a jet connected to said feed pipe and arranged to deliver material towards said atomizer ow surface, said scoop and said jet constituting branches of said feed pipe, a valve having an outlet connected to the feed Pineau@ having an inlet adapted@ be renamed te a. source of material A"supply, means `defining a chamber in communication with the outlet 'of said valve, 'and means automatically operable in response to the actuation vof said valve for "expanding lsaid chamber while said valve is being` operated towards closed position for creating a suction'which drawsk the -material from the scoop, the scoop chamber and thel jet, whereby spray operations are substantially instantaneously shut off, and for lc'ontracting said Achamber 4while said valve is operating toward open position for forcing material back into said scoop, lscoop chamber and iet, whereby spray operations are substantially instantaneously restarted.

2. Aspraying system as described in claim l, wherein said valve vhas la movable valve member, said chamber defining ymeans comprises a bellows having an end wall movable along theaxis o'fthe bellows, and said automatic chamber expanding and contracting :means comprises la rigid connection lbetween v`the movable valve member and said..movable end wall, Vand wherein means are pro-Y vided for moving the end wall of said bellows rin either direction kalong the `axis ofthe` bellows for valve opening and-closing operations.

vEl. A cspraying system as'described in claim 1, wherein said valve comprises a Vport between 'the inlet and outlet, a-movable valve `member in the form of a poppet slidable in -said-portland-havingsa body portion with a snug slide t in the port and terminating uin a reduced end section, said body portion'while in said port blocking vtlow therethrough `to prevent dissipation of material therethrough while "the charnberis expanding and contracting.

4. In a centrifugalspray device, a rotatable atomizer defining van annular ow surface along which the :material to be sprayed ilows under centrifugal action and having a peripheral discharge edge, a rotary bowl having itsfaxis tilted in relation tothe axis of said atomizer yfor intercepting part ofthe spray vprojected `from said edge 'and collecting the intercepted material, means forming in said Ibowl an annular scoop chamber extending radially outwardly vand rotatable with said bowl, ysaid scoop chamber having means to cause -the material intercepted in fthe bowl to ow thereinto, a stationary scoop disposed in'said scoop chamberandarranged to dip at its-nose end into and receive material from the ,outer periphery ,of said scoop chamber as ,said-'scoop chamber rotates, an

inlet feed pipe arranged to :deliver fresh material tothe y device, said -scoop :near its other -end having a connection with said feed pipe, and .azjetconnected to said feed pipe and arranged to deliver material towards said atomizer ow surface, said jet having a pressure responsive valve operable to open when the pressure in said jet exceeds a predetermined amount, said scoop and said jet constituting branches of said feed pipe.

5. In a centrifugal spray device, a rotatable atomizer defining an annular ow surface along which the material to vbe sprayed ows under centrifugal action and having a peripheral discharge edge, a rotary bowl having its axis tilted in relation to the axis of said atomizer `for intercepting part of the spray projected from said edge and collecting the intercepted material, means forming in said bowl an annular scoop chamber extending radially outwardly and rotatable with said bowl, said scoop chamber having means to cause the material intercepted in the bowl to flow thereinto, a stationary scoop disposed in said scoop chamber and arranged to dip at `its nose end into and receive material from the outer periphery of said scoop chamber as said scoop chamber rotates, an inlet feed pipe arranged to deliver fresh material to the device, said scoop near its other end having a connection with said feed pipe, and a jet connected to said feed pipe and arranged to deliver material towards said atomizer flow surface, said jet having a pressure responsive valve with means for opening said valve automatically and to an extent depending on the ademas ll pressure in said jet, said scoop and said jet constituting branches of said feed pipe.

6. In a centrifugal spray device, a rotatable atomizer defining an annular radially extending ow surface along which the material to be sprayed flows under centrifugal action and having a peripheral discharge edge, said atomizer being electrically conductive and being adapted to be connected to a source of current to produce an electrostatically atomized spray, and means for deflecting the air away from the atomizer ow surface to prevent the creation of ionized air in thevicinity of said discharge edge, said air deecting means comprising an electrically non-conductive hub secured to said atomizer for rotation therewith and having an annular radially extending surface confronting said atomizer ow surface and contoured axially away from said atomizer ow surface in a radially outward direction to deflect the air away from said atomizer flow surface.

7. A spraying system comprising a centrifugal spray device including a rotatable atomizer defining an annular flow surface along which the material to be sprayed flows under centrifugal action and having a peripheral discharge edge, a rotary bowl having its axis tilted in relation to the axis of said atomizer for intercepting part of the spray projected from said edge and collecting the intercepted material, means forming in said bowl an annular scoop chamber extending radially outwardly and rotatable with said bowl, said scoop chamber having means to cause the material intercepted in the bowl to ow thereinto, a stationary scoop disposed in said scoop chamber and arranged with its nose end at the outer periphery of said scoop chamber, means including a feed pipe forming a supply duct arranged to deliver fresh material to said centrifugal spray device, a cut-off valve in said feed pipe for interrupting the ow of material therethrough, means forming an expansible chamber connected in said feed pipe between said cut-olf valve and said centrifugal spray device and forming a part of said supply duct, means connecting said scoop to feed material from said scoop chamber into said supply duct at a point between said cut-off valve and said centrifugal spray device, and means automatically operable in response to the actuation of said cut-off valve for expand'- ing said chamber while said valve is being operated toward closed position for creating a suction which draws the material from the scoop whereby spray operations are substantially instantaneously cut off, and for contracting said chamber while said valve is operating to ward open position for forcing material back into said scoop and to said centrifugal spray device, whereby spray operations are substantially instantaneously restarted.

8. A spraying system comprising a centrifugal spray device including a rotatable atomizer defining an annular ow surface along which the material to be sprayed ows under centrifugal action and having a peripheral discharge edge, a rotary bowl having its axis tilted in relation to the axis of said atomizer for intercepting part of the spray projected from said edge and collecting the intercepted material, means forming in said bowl an an nular scoop chamber extending radially outwardly and rotatable with said bowl, said scoop chamber having means to cause the material intercepted in the bowl to flow thereinto, a stationary scoop disposed in said scoop chamber and arranged with its nose end at the outer periphery of said scoop chamber, means including a feed pipe forming a supply duct arranged to deliver fresh material to said centrifugal spray device, a cut-out valve in said feed pipe for interrupting the ow of material therethrough, means forming an expansible chamber connected in said feed pipe between said cut-off valve and said centrifugal spray device and forming a part of said supply duct, a check valve in said duct between said chamber and said centrifugal spray device to prevent reverse flow of material from said spray device, means connecting said scoop to feed material from said v scoop chamber into said supply duct at a point between References Cited in the tile of this patent UNITED STATES PATENTS Norris Dec. 8, 1936 2,063,048 2,545,489 Norris Mar. 20, 1951 2,901,177 Norris Aug. 25, 1959 

